This paper describes zeroand first-order derivative spectrophotometric methods for determination of estradiol valerate in pharmaceutical preparations. The solutions of the standard and pharmaceutical samples were prepared in methanol. Absorbances of estradiol valerate were measured at 280 nm for zero-order by measuring height of peak from zero, at 292 nm for first-order derivative spectrophotom...

Methylxylenol blue or S^'-bis-Z^jiV'-diicarboxymethylJaminomethyl-^-xylenolsulfonephthalein belongs to the group of metallochromic indicators prepared by Körbt and Přibil [1] via condensation of common sulfonephthalein dyes with formaldehyde and iminodiacetic acid. Recently it has been newly prepared by Cherkesov and co-workers [2] and named ^-xylenolphthalexon S. Two indicators from this group...